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Greenland may have another massive crater hiding under its ice

Greenland's ice may be hiding more than one crater left by long-ago meteorite impacts.

An analysis of satellite and airborne images of the topography beneath the ice sheet has revealed a large, craterlike structure buried beneath two kilometers of ice. It's just 183 kilometers southeast of Hiawatha, another possible large impact crater described in November (SN: 12/8/18, p. 6). The newfound bowl-shaped object is about 36.5 kilometers across, slightly larger than the 31-kilometer-wide Hiawatha depression, researchers report online February 11 in Geophysical Research Letters.

Like Hiawatha, the new feature consists of a ring-shaped rim surrounding a depression with a peak at its center — consistent with a crater carved out by the impact of a large meteorite, says coauthor Joseph MacGregor, a glaciologist with NASA's Operation IceBridge. Unlike Hiawatha, there's little chance of collecting geologic data from the new structure to confirm or deny an extraterrestrial origin: Instead of sitting at the edge of the ice sheet, the new depression is closer to the center of the ice.

[...] "It's simply not that unusual," says coauthor William Bottke, a planetary scientist at the Southwest Research Institute in Boulder, Colo. Scientists already know of two such pairs — one in Ukraine and another in Canada — but, statistically, a third pair is plausible too, Bottke says.

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